JP6479074B2 - Magnetic composition, inductor and magnetic body - Google Patents

Description

  The present invention relates to a magnetic composition, an inductor, and a magnetic body.

  Increasing the efficiency of power converters is an important consideration in response to industry needs for high performance. Factors affected by the efficiency of a power converter can be broadly divided into switch loss and passive element loss. The switch loss can be divided into IGBT (insulated gate bipolar mode transistor) and diode loss, and the passive element loss can be divided into inductor and capacitor loss.

  Among these, the loss of the inductor includes the copper loss of the load-dependent loss that increases as the size of the load applied to the inductor increases, and the iron loss of the load independent loss that has a constant magnitude regardless of the load. (Iron loss). Copper loss refers to loss that occurs due to the winding resistance of the inductor, and iron loss refers to loss that occurs when driving in continuous conduction mode at a constant switching frequency.

  The load-dependent loss affects the efficiency in the entire load region, and is particularly affected by the conduction loss. On the other hand, load independent loss has a small change ratio due to load, so the ratio of heavy load is small, but light load occupies a larger specific gravity than load-dependent loss, so the efficiency at light load is reduced. To improve, it can be considered effective to reduce the load independent loss.

  The iron loss greatly varies depending on the magnetic flux density, and is classified into a hysteresis loss and an eddy current loss. Hysteresis loss is affected by factors due to impurities, potential, grain boundaries, and powder interfaces in the inductor, and eddy current loss occurs in the powder particles contained in the main body. It may increase depending on the degree of insulation.

  There is a method of reducing the particle size in order to reduce the eddy current loss. However, when the particle size decreases, there is a problem in that the inductance decreases because the magnetic permeability decreases.

  Thus, there is a need for a method that can reduce eddy current loss.

Korean Published Patent No. 2015-0043038 Korean Published Patent No. 2015-0059731

  The present invention relates to a magnetic composition capable of ensuring high efficiency and inductance by reducing eddy current loss and an inductor including the same.

  An embodiment of the present invention includes first, second, and third metal magnetic particles, wherein the metal magnetic particles have a first metal magnetic particle having an average particle size of 10 to 28 μm, and an average particle size of 1 to Provided is a magnetic composition comprising second metal magnetic particles having a thickness of 4.5 μm and third metal magnetic particles having an insulating film formed on the surface and having a particle size of 300 nm or less.

  Another embodiment of the present invention includes a main body including metal magnetic particles and a coil portion disposed in the main body, and the metal magnetic particles have a first metal magnetic particle having an average particle diameter of 10 to 28 μm. Provided is an inductor including particles, second metal magnetic particles having an average particle diameter of 1 to 4.5 μm, and third metal magnetic particles including an insulating film disposed on a surface and having a particle diameter of 300 nm or less. To do.

  Still another embodiment of the present invention is a resin, dispersed in the resin, the first metal magnetic particles having an average particle size of 10 to 28 μm, and the resin between the first metal magnetic particles, A second metal magnetic particle having an average particle diameter of 1 to 4.5 μm and an insulating film dispersed on the resin between the first and second metal magnetic particles and disposed on the surface, and having a particle diameter of 300 nm A magnetic body including the following third metal magnetic particles is provided.

  Still another embodiment of the present invention includes metal magnetic particles dispersed in a resin, the metal magnetic particles including an insulating film disposed on a surface, and first metal magnetic particles having a particle size of 300 nm or less; Second metal magnetic particles having an average particle diameter of 1 to 28 μm, and the content of the first metal magnetic particles is 1 to 1 when the content of the metal magnetic particles in the magnetic composition is 100 wt%. When the content of the metal magnetic particles in the magnetic composition is 100 wt%, the second metal magnetic particles provide a remaining magnetic composition.

  According to one embodiment of the present invention, it is possible to improve the eddy current loss of the inductor and ensure high efficiency and inductance.

1 schematically shows a perspective view of an inductor according to an embodiment of the present invention. FIG. 2 schematically shows a cut surface in the II ′ direction of FIG. 1, and schematically shows a cross-sectional view of an inductor according to an embodiment of the present invention. FIG. 3 schematically shows an enlarged view of a portion A in FIG. 2. 6 is a scanning electron microscope (SEM) showing a cross-sectional structure of the inductor body according to the content of third metal magnetic particles. It is a graph which shows the change of Q value by the frequency of an inductor by content of the 3rd metal magnetic particle.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. However, the embodiments of the present invention can be modified in various other forms, and the scope of the present invention is not limited to the embodiments described below. In addition, the embodiments of the present invention are provided to more fully explain the present invention to those skilled in the art. Accordingly, the shape and size of the elements in the drawings may be enlarged / reduced (or highlighted or simplified) for a clearer description.

  The magnetic composition according to the present invention will be described below.

  A magnetic composition according to an embodiment of the present invention includes metal magnetic particles, and the metal magnetic particles include first metal magnetic particles having an average particle diameter of 10 to 28 μm and average particle diameters of 1 to 4.5 μm. It includes certain second metal magnetic particles and third metal magnetic particles including an insulating film formed on the surface and having a particle size of 300 nm or less.

  The magnetic composition may include metal magnetic particles and a resin, and the metal magnetic particles may be dispersed in the resin.

  The metal magnetic particles include at least one selected from the group consisting of iron (Fe), silicon (Si), chromium (Cr), aluminum (Al), nickel (Ni), and cobalt (Co). For example, it can be an Fe—Si—Cr alloy.

  The resin may be a thermosetting resin such as an epoxy resin or a polyimide resin.

  The metal magnetic particles include first, second, and third metal magnetic particles having different sizes. Specifically, the first metal magnetic particles have an average particle size of 10 to 28 μm, the second metal magnetic particles have an average particle size of 1 to 4.5 μm, and the third metal magnetic particles are 300 nm. Satisfies having the following particle size. That is, the first metal magnetic particles can be coarse powder, the second metal magnetic particles can be fine powder, and the third metal magnetic particles can be ultrafine powder.

  The first metal magnetic particles reduce the hysteresis loss of the magnetic composition in the low frequency band and minimize the eddy current loss of the magnetic composition in the high frequency band. , Having an average particle size of 10 to 28 μm.

  The second metal magnetic particles may have an average particle size of 1 to 4.5 μm in order to increase a saturation current (Isat) of the magnetic composition. In order to reduce the powder filling rate and eddy current loss, it has a particle size of 300 nm or less.

  In general, when the size of the metal magnetic particles is reduced, eddy current loss can be reduced. However, since the magnetic permeability of the inductor body is reduced, it is difficult to realize inductance that is a main factor in the inductor.

  A magnetic composition according to an embodiment of the present invention includes third metal magnetic particles including an insulating film formed on a surface and having a particle size of 300 nm or less. Thereby, the eddy current loss can be reduced by including the third metal magnetic particles having a small particle size, and the inductance can be secured by the insulating film formed on the surface of the third metal magnetic particles.

  The insulating film may be an oxide film, may be formed of one or more layers, and may have a maximum of three layers.

  The insulating film can be made of FeO in the case of one layer, and can have one structure selected from FeO / SiO and FeO / CrO in the case of two layers, and FeO / in the case of three layers. It can have a CrO / SiO structure.

  When the insulating film is a single layer made of FeO, it can have excellent magnetic properties in terms of the characteristics of the thin insulating film.

  In the case where the insulating film has two layers, the insulating film is formed on the surface of the core and is formed on the first layer made of FeO and the selected one of SiO and CrO. And a second layer. The thickness of the second layer may be the same as or smaller than the thickness of the first layer. SiO has excellent insulating properties, and CrO can play a role in preventing rapid oxidation that may occur because the surface of the core is exposed to the air.

  When the insulating film has three layers, an insulating film is formed on the core. The insulating film is formed on the surface of the core, and is formed on the first layer made of FeO and the first layer. And a third layer made of SiO and formed on the second layer. The thickness of each layer may be the same or different.

  The three-layer insulating film has a structure including FeO, SiO and CrO layers, can prevent the surface oxidation of the core and have excellent insulating characteristics, and improve the efficiency of the inductor by reducing eddy current loss. be able to.

  The insulating film may have a thickness of 1 to 20% of a particle size of the third metal magnetic particle.

  If the thickness of the insulating film exceeds 20% of the particle size of the third metal magnetic particles, the magnetic permeability and the magnetic susceptibility may be reduced. Therefore, it is preferable to make the thickness as thin as possible.

  The content of the first metal magnetic particles is 70 to 79 wt%, the content of the second metal magnetic particles is 10 to 20 wt%, and the content of the third metal magnetic particles with respect to 100 wt% of the metal magnetic particles. Satisfies 1 to 20 wt%.

  Due to the magnetic permeability of the inductor, the content of the first metal magnetic particles may be 70 to 79 wt% with respect to 100 wt% of the metal magnetic particles, and the content of the second metal magnetic particles may be It may be 10 to 20 wt% with respect to 100 wt% of the metal magnetic particles.

  In order to reduce eddy current loss and improve inductance, the content of the third metal magnetic particles may be 1 to 20 wt% with respect to 100 wt% of the metal magnetic particles.

  If the content of the third metal magnetic particles is less than 1 wt%, the effect of improving the inductance is not sufficient, and if the content of the third metal magnetic particles exceeds 20 wt%, the filling factor of the inductor body increases. The inductance can be increased, but the Q value (Q factor) is decreased. Therefore, the content of the third metal magnetic particles is preferably 1 to 20 wt%.

  The magnetic composition according to an embodiment of the present invention includes third metal magnetic particles having a particle size of 300 nm or less and including an insulating film formed on the surface. By increasing and reducing eddy current loss, inductance can be improved and high efficiency can be achieved.

  Hereinafter, an inductor according to the present invention will be described with reference to the accompanying drawings.

  FIG. 1 schematically shows a perspective view of an inductor according to an embodiment of the present invention, and FIG. 2 schematically shows a cut surface in the II ′ direction of FIG. FIG. 3 schematically shows a sectional view of an inductor according to an example, and FIG. 3 schematically shows an enlarged view of a portion A in FIG.

  1 to 3, an inductor 100 according to an embodiment of the present invention includes a main body 50 including metal magnetic particles 61, 63, and 65, and coil portions 20, 41, and 42 disposed in the main body. In addition, the metal magnetic particles include first metal magnetic particles 61 having an average particle diameter of 10 to 28 μm, second metal magnetic particles 63 having an average particle diameter of 1 to 4.5 μm, and an insulating film formed on the surface And third metal magnetic particles 65 having a particle diameter of 300 nm or less.

  The main body 50 has an external appearance of the inductor. The main body 50 may have one surface, a lower surface facing the one surface, and a surface connecting the one surface and the other surface. L, W, and T shown in FIG. 1 indicate the length direction, the width direction, and the thickness direction, respectively. The main body 50 may have a hexahedral shape including an upper surface and a lower surface facing the stacking direction (thickness direction) of the coil layer, an end surface facing the length direction, and a side surface facing the width direction. When mounted on the substrate, the lower surface (other surface) of the main body may be a mounting surface in contact with the printed circuit board. The angle at which each surface contacts may be rounded by grinding or the like, but is not limited thereto.

  The main body 50 includes a magnetic material exhibiting magnetic characteristics.

  The main body 50 can be formed by forming a coil portion, laminating sheets containing a magnetic substance on the upper and lower portions, and then crimping and curing the sheet. The magnetic substance may be a resin containing metal magnetic particles.

  Referring to FIG. 3, the main body 50 may have a form in which metal magnetic particles 61, 63, 65 are dispersed in a resin 60.

  The metal magnetic particles 61, 63, 65 include at least one selected from the group consisting of iron (Fe), silicon (Si), chromium (Cr), aluminum (Al), and nickel (Ni). And can be an Fe-Si-Cr alloy.

  The resin 60 may be a thermosetting resin such as an epoxy resin or a polyimide resin.

  The eddy current loss of the inductor increases with the particle size and the degree of particle insulation, and the eddy current loss increases as the frequency increases. As a method of reducing the eddy current loss, there is a method of reducing the size of the metal magnetic particles contained in the main body. However, when the metal magnetic particle size is reduced, the magnetic permeability of the main body is reduced and the inductance value of the inductor is reduced. Problem occurs.

  Referring to FIG. 3, an inductor body 50 according to an embodiment of the present invention includes an insulating film 65 b formed on a surface thereof, and includes third metal magnetic particles 65 having a particle size of 300 nm or less. Since the loss can be reduced and the filling rate of the metal magnetic particles in the main body is increased, the inductance can be ensured.

  The insulating film 65b may be an oxide film, may be formed of one or more layers, and may have a maximum of three layers. For example, the insulating film 65b may include a maximum of three layers formed of different materials.

  The insulating film 65b can be made of FeO in the case of one layer, can have one structure selected from FeO / SiO and FeO / CrO in the case of two layers, and FeO in the case of three layers. / CrO / SiO structure.

  When the insulating film has one layer made of FeO, it can have excellent magnetic characteristics in terms of the characteristics of the thin insulating film.

  When the insulating film 65b has two layers, an insulating film is formed on the surface of the core 65a, and is formed on the first layer 65b ′ made of FeO and the first layer, and one selected from SiO and CrO. And a second layer 65b ″ made of two. The thickness Db ″ of the second layer may be the same as or smaller than the thickness Db ′ of the first layer. SiO has excellent insulating properties, and CrO can play a role in preventing rapid oxidation that may occur because the surface of the core is exposed to the air.

  When the insulating film 65b is composed of three layers, an insulating film is formed on the core, and the insulating film is formed on the surface of the core, and is formed on the first layer 65b ′ made of FeO and the first layer. The structure may include a second layer 65b ″ made of CrO and a third layer 65b ′ ″ made of SiO and formed on the second layer. The thickness of each layer may be the same or different.

  The three-layer insulating film has a structure including FeO, SiO and CrO layers, can prevent the surface oxidation of the core and have excellent insulating characteristics, and improve the efficiency of the inductor by reducing eddy current loss. be able to.

  The insulating film may have a thickness of 1 to 20% of a particle size of the third metal magnetic particle.

  If the thickness of the insulating film exceeds 20% of the particle size of the third metal magnetic particles, the magnetic permeability and the magnetic susceptibility may be reduced. Therefore, it is preferable to make the thickness as thin as possible.

  Due to the magnetic permeability of the inductor, the content of the first metal magnetic particles 61 may be 70 to 79 wt% with respect to 100 wt% of the metal magnetic particles of the magnetic composition. The content of the particles 63 may be 10 to 20 wt% with respect to 100 wt% of the metal magnetic particles of the magnetic composition.

  In order to reduce eddy current loss and improve inductance, the content of the third metal magnetic particles 65 may be 1 to 20 wt% with respect to 100 wt% of the metal magnetic particles.

  If the content of the third metal magnetic particles is less than 1 wt%, the effect of improving the inductance is not sufficient, and if the content of the third metal magnetic particles exceeds 20 wt%, the filling factor of the inductor body increases. The inductance can be increased, but the Q value (Q factor) is decreased. Therefore, the content of the third metal magnetic particles is preferably 1 to 20 wt%.

  Table 1 below shows the inductance of the inductor depending on the content of the third metal magnetic particles. Each sample used the same size and material, and differed only in the content of the third metal magnetic particles.

  Referring to Table 1, it can be seen that the inductance capacity of the inductor increases to 20 wt% as the content of the third metal magnetic particles increases. This is considered to be caused by an increase in the magnetic permeability of the main body accompanying an increase in the powder filling rate of the main body of the inductor.

  It can also be seen that when the content of the third metal magnetic particles exceeds 20 wt%, the inductance of the inductor decreases again.

  FIG. 4 is a scanning electron microscope (SEM) showing a cross-sectional structure of the inductor body according to the content of the third metal magnetic particles.

  The main body includes first metal magnetic particles having an average particle diameter of 10 to 28 μm, second metal magnetic particles having an average particle diameter of 1 to 4.5 μm, and an insulating film formed on the surface. And third metal magnetic particles having a thickness of 300 nm or less.

  Referring to FIG. 4, a third metal magnetic particle having an ultrafine powder is included between the first metal magnetic particle and the second metal magnetic particle, and the powder filling of the main body as the content of the third metal magnetic particle increases. It can be seen that the rate increases.

  FIG. 5 is a graph showing changes in the Q value according to the frequency of the inductor depending on the content of the third metal magnetic particles.

  Referring to FIG. 5, as the content of the third metal magnetic particles increases, the powder filling rate of the main body increases, so that the parasitic capacitance affecting the resonance frequency decreases and the Q value decreases. It is judged. On the other hand, it can be seen that when the content of the third metal magnetic particles exceeds 20 wt%, the Q value is significantly reduced.

  The coil part plays a role of performing various functions in the electronic device through characteristics expressed from the coil of the inductor 100. For example, the inductor 100 may be a power inductor. In this case, the coil part can store the electricity in the form of a magnetic field to maintain the output voltage and stabilize the power source.

  The coil portion includes first and second coil patterns 41 and 42 formed on the upper surface and the lower surface of the support member 20, respectively. The first and second coil patterns 41 and 42 are coil layers disposed relative to the support member 20.

  The first and second coil patterns 41 and 42 can be formed using a photolithography method or a plating method.

  The support member 20 is not particularly limited in material or type as long as it can support the first and second coil patterns 41 and 42. For example, a copper foil laminate (CCL), polypropylene glycol (PPG) ) A substrate, a ferrite substrate, a metal-based soft magnetic substrate, or the like. Further, it may be an insulating substrate made of an insulating resin. As the insulating resin, a thermosetting resin such as an epoxy resin, a thermoplastic resin such as polyimide, or a resin in which a reinforcing material such as glass fiber or an inorganic filler is impregnated, for example, a prepreg, ABF ( Ajinomoto Build-up Film (FR-4), BT (Bismaleimide Triazine) resin, PID (Photo Imageable Dielectric) resin, or the like can be used. In terms of maintaining rigidity, an insulating substrate containing glass fiber and epoxy resin can be used, but is not limited thereto.

  In the upper and lower surfaces of the support member 20, the core portion 55 can be formed by penetrating the central portion to form a hole and filling the hole with a magnetic material such as ferrite or metal magnetic particles. By forming the core portion filled with the magnetic material, the inductance (L) can be improved. The core portion can be filled with the same material that forms the body 50.

  The first coil pattern 41 and the second coil pattern 42 stacked on both surfaces of the support member 20 are electrically connected via vias 45 penetrating the support member.

  The via 45 can be formed by forming a through hole penetrating the support member 20 using a mechanical drill, a laser drill, or the like and then filling the inside of the through hole with a conductive material by plating.

  The via 45 may have any shape or material as long as it can electrically connect the upper first coil pattern 41 and the lower second coil pattern 42 respectively disposed on both surfaces of the support member 20. Is not particularly limited. Here, the upper side and the lower side are determined based on the lamination direction of the coil patterns in the drawing.

  The via 45 is made of a conductive material such as copper (Cu), aluminum (Al), silver (Ag), tin (Sn), gold (Au), nickel (Ni), lead (Pb), or an alloy thereof. Can be included.

  The cross section of the via 45 may have a trapezoidal shape or an hourglass shape.

  The cross section of the via 45 may have an hourglass shape. The shape can be realized by processing the upper surface or the lower surface of the support member. Thereby, the cross-sectional width of the via can be reduced. The via may have a cross-sectional width of 60 to 80 μm, but is not limited thereto.

  The first and second coil patterns 41 and 42 are covered with an insulating layer (not shown) and are not in direct contact with the magnetic material forming the main body 50 and the core portion 55.

  The insulating layer serves to protect the first and second coil patterns.

  Any material can be applied as long as the material of the insulating layer contains an insulating material, for example, an insulating material used for a normal insulating coating, for example, an epoxy resin, a polyimide resin, a liquid crystal crystalline polymer resin, etc. A known photosensitive insulating (PID) resin can be used, but the present invention is not limited thereto.

  Referring to FIGS. 1 and 2, the first and second external electrodes 81 and 82 formed on both end surfaces of the main body 50 are electrically connected to the first and second coil patterns 41 and 42.

  The first and second external electrodes 81 and 82 are electrically connected to the respective lead terminals of the first and second coil patterns 41 and 42 exposed at both end surfaces of the main body 50.

  The first and second external electrodes 81 and 82 serve to electrically connect the coil portion in the inductor to the electronic device when the inductor is mounted on the electronic device.

  The first and second external electrodes 81 and 82 can be formed using a conductive paste containing a conductive metal, and the conductive metal includes copper (Cu), nickel (Ni), and tin (Sn). , And at least one of silver (Ag) or an alloy thereof.

  The first and second external electrodes may include a plating layer formed on the paste layer.

  The plating layer may include any one or more selected from the group consisting of nickel (Ni), copper (Cu), and tin (Sn), for example, a nickel (Ni) layer and tin (Sn). The layers may be formed in order.

  Although the embodiments of the present invention have been described in detail above, the technical scope of the present invention is not limited thereto, and various modifications can be made without departing from the technical idea of the present invention described in the claims. And that variations are possible will be apparent to those of ordinary skill in the art.

DESCRIPTION OF SYMBOLS 100 Inductor 20 Support member 41 1st coil pattern 42 2nd coil pattern 45 Via 50 Main body 55 Core part 60 Resin 61 1st metal magnetic particle 63 2nd metal magnetic particle 65 3rd metal magnetic particle 81 1st external electrode 82 2nd External electrode

Claims (17)

Containing metal magnetic particles,
The metal magnetic particles are
First metal magnetic particles having an average particle size of 10 to 28 μm;
Second metal magnetic particles having an average particle diameter of 1 to 4.5 μm;
Including a third metal magnetic particle including an insulating film disposed on a surface and having a particle size of 300 nm or less,
The insulating film is composed of three layers and is FeO / CrO / SiO.
Magnetic material composition. The magnetic composition further includes a resin,
The metal magnetic particles are dispersed in the resin,
The second metal magnetic particles are dispersed in the resin between the first metal magnetic particles,
The magnetic composition according to claim 1 , wherein the third metal magnetic particles are dispersed in the resin between the first and second metal magnetic particles. The content of the first metal magnetic particles is 70 to 79 wt%, the content of the second metal magnetic particles is 10 to 20 wt%, and the content of the third metal magnetic particles with respect to 100 wt% of the metal magnetic particles. The magnetic composition according to claim 1 or 2 , wherein 1 to 20 wt% is satisfied. The thickness of the insulating film is 1 to 20% of the diameter of the third metal magnetic particles, magnetic composition according to any one of claims 1 to 3. Including resin,
The magnetic material composition according to claim 1, wherein the metal magnetic particles are dispersed in the resin. The metal magnetic particles include at least one selected from the group consisting of iron (Fe), silicon (Si), chromium (Cr), aluminum (Al), and nickel (Ni). 6. The magnetic composition according to any one of 5 above. A body containing metal magnetic particles;
A coil portion disposed in the main body,
The metal magnetic particles include first metal magnetic particles having an average particle diameter of 10 to 28 μm, second metal magnetic particles having an average particle diameter of 1 to 4.5 μm, and an insulating film disposed on the surface. Third metal magnetic particles having a particle size of 300 nm or less,
The insulating film is composed of three layers and is FeO / CrO / SiO.
Inductor. The metal magnetic particles are dispersed in a resin,
The second metal magnetic particles are dispersed in the resin between the first metal magnetic particles,
The inductor according to claim 7 , wherein the third metal magnetic particles are dispersed in the resin between the first and second metal magnetic particles. The content of the first metal magnetic particles is 70 to 79 wt%, the content of the second metal magnetic particles is 10 to 20 wt%, and the content of the third metal magnetic particles with respect to 100 wt% of the metal magnetic particles. The inductor according to claim 7 or 8 , which satisfies 1 to 20 wt%. The thickness of the insulating film, the third is 1-20% of the particle size of the metal magnetic particles, an inductor according to any one of claims 7 to 9. The metal magnetic particles of iron (Fe), containing silicon (Si), chromium (Cr), aluminum (Al), and any one or more selected from the group consisting of nickel (Ni), claims 7 The inductor according to any one of 10 . The body includes a resin;
The metal magnetic particles are form dispersed in the resin, an inductor according to any one of claims 7 11. The inductor according to claim 12 , wherein the resin is a thermosetting resin. Resin,
The first metal magnetic particles dispersed in the resin and having an average particle diameter of 10 to 28 μm, and the first metal magnetic particles dispersed in the resin between the first metal magnetic particles and having an average particle diameter of 1 to 4.5 μm. Metal magnetic particles,
A third metal magnetic particle including an insulating film dispersed on the resin between the first and second metal magnetic particles and disposed on the surface, and having a particle size of 300 nm or less;
The insulating film is composed of three layers and is FeO / CrO / SiO.
Magnetic body. The magnetic body further includes a coil portion disposed in the magnetic body,
The magnetic body according to claim 14 , wherein the resin and the first to third metal magnetic particles are disposed so as to surround the coil portion, and extend to a hole in a central portion of the coil portion to form a core portion. Body. When the content of the first to third metal magnetic particles dispersed in the resin is 100 wt%, the content of the first metal magnetic particles is 70 to 79 wt%, and the content of the second metal magnetic particles The magnetic main body according to claim 14 or 15 , wherein 10 to 20 wt% and the third metal magnetic particles are 1 to 20 wt%. The thickness of the insulating film is 1 to 20% of the diameter of the third metal magnetic particles, the magnetic body according to any one of claims 14 to 16.